Researchers in the UK have identified a connection between congenital heart disease in newborns and maternal anaemia during early pregnancy. According to the study, which surveyed data from 16,500 mothers, maternal anaemia within the first 100 days of pregnancy increases the risk of congenital heart disease by 47% compared to the baseline risk of around one in 100. This finding comes after accounting for other risk factors, including the mother's age.
The research, led by Associate Professor Duncan Sparrow at the University of Oxford, marks a first for the UK in studying this link. “We already know that the risk of congenital heart disease can be raised by a variety of factors, but these results develop our understanding of anaemia specifically and take it from lab studies to the clinic. Knowing that early maternal anaemia is so damaging could be a gamechanger worldwide," Sparrow stated.
In the UK, approximately a quarter of pregnant women suffer from anaemia, and this figure rises to over a third globally. The condition is associated with problems later in pregnancy, such as low birth weight and premature delivery. However, its effects during early pregnancy were less understood until now.
The study compares anaemia rates in mothers with children diagnosed with congenital heart disease to those without. Among mothers with affected children, 4.4% had anaemia, compared with 2.8% in the control group. The original research was based on experiments involving mice, which prompted the human study using anonymized data from GP records.
The study highlights the potential significance of iron supplementation. Many anaemia cases arise from iron deficiency, suggesting that iron supplements for women attempting to conceive or already pregnant might prevent congenital heart disease in newborns. Dr Sonya Babu-Narayan of the British Heart Foundation commented on the potential impact: “If low iron turns out to be one of the culprits, then replenishing iron levels during early pregnancy when the baby's heart is forming could have significant benefits for a baby's lifelong heart health.”
There remain uncertainties and challenges to address, such as confirming that iron deficiency anaemia directly causes congenital heart disease, which researchers intend to explore. Larger studies could validate the findings further and specify which types of congenital heart disease relate more closely to anaemia. Despite these uncertainties, Dr Babu-Narayan highlighted that individual risk remains relatively low, even with the increase suggested by the study, particularly without a family history of the condition.
The detailed findings are published in the paper 'Maternal Anaemia and Congenital Heart Disease in Offspring: A Case–Control Study Using Linked Electronic Health Records in the United Kingdom,' available in BJOG.